The expedition in search of the world’s most endangered marine mammal reports a population decline

Mexico number the critically endangered vaquita The number of harbor porpoises seen in the Gulf of California dropped to between 6 and 8 this year, researchers said Tuesday, although it’s possible some of the creatures may have moved elsewhere in the Gulf, the only place in the world where they live.

Vaquitas are the smallest pigs in the world and the most endangered marine mammal on the planet.

Last year, experts on a monitoring expedition estimated they saw between 10 and 13 of the tiny, shy and elusive porpoises during a nearly two-week cruise in the Gulf, also known as the Sea of ​​Cortez.

But this year, conservation group Sea Shepherd said a similar expedition conducted over three weeks in May saw only about half a dozen, although the search was not as extensive as last year’s. More worryingly, no baby vaquitas were seen this year.

“Unlike 2023, no recently born calf was seen, but a healthy juvenile was seen,” Sea Shepherd said in a statement.

However, about half of the sightings last year occurred outside and just west of the exclusive vaquita protection zone, a heavily patrolled area in the Gulf where all fishing is prohibited. some still happen illegally.

Experts aren’t exactly sure why vaquitas might like the area outside the protected area, but this year’s expedition focused on areas inside the area.

Because they are so small and elusive, many times vaquitas can only be seen from a distance through powerful binoculars, and thus such sightings are categorized as possible or probable. Thus, the numbers are expressed in the possible “range” of the real figure.

Mammals also emit “clicks” that can be heard through acoustic monitoring equipment.

“While these results are concerning, the area surveyed represents only 12% of the total area where vaquitas were observed in 2015,” said Dr Barbara Taylor, the researcher who led the study. “Since vaquitas move freely within the vaquita sanctuary, we need to expand the study by using acoustic detection to determine where the vaquitas are going.”

There are plans to do just that. But according to the previous report, “fishers are beginning to remove the acoustic devices (CPODs) used to record vaquita clicks. The data recorded on each device is lost, and it is expensive to replace stolen CPODs.”

“As long as enforcement of the fishing ban is not effective and gear theft is not stopped, acoustic monitoring cannot collect data as it has done in the past,” the report states.

An endangered species

Last year’s report raised hopes for the species, which lives nowhere else and cannot be captured, kept or bred in captivity. In 2018 an attempt was made to capture some vaquitas and help them breed in captivity, but the first pig captured was “simply too stressed by the experience” and had to be released. CBS News previously reported.

This year’s report was another installment continued bad news for the species. Illegal gill nets have trapped and killed vaquitas for decades; the reported population has declined from nearly 600 vaquitas in 1997.

Fishermen set their nets to catch totoaba, a swim bladder fish considered a delicacy in China that can fetch thousands of dollars per pound. The size of the nets is about the size of a vaquita’s head, CBS News reported, making it easy for them to become ensnared in the net.

WHEREAS The Mexican government has made some efforts to stop net fishing – such as sinking concrete blocks with hooks to catch nets in the protected area – fishermen still seem to have the upper hand, setting illegal nets regularly and even sabotaging monitoring efforts.

Alex Olivera, Mexico’s representative for the Center for Biological Diversity, said that “vaquitas reproduce so slowly that recovery is impossible without help, and their very survival remains in serious doubt.”

“Vaquitas face a serious threat of extinction from dangerous gillnets in their habitat and weak enforcement of conservation rules by the Mexican government,” Olivera said, noting “it is essential” that enforcement be stepped up now.

Olivera, who was not part of the expedition, previously estimated that “even in a habitat without nets, it will take about 50 years for the population to return to where it was 15 years ago.”

A scientist told CBS News in 2018 that removing the gill nets could help protect the species.

“If we can make absolutely sure that these underwater nets are not in a place where the remaining animals are, they will survive,” explained the scientist. “They just need a chance.”

The administration of President Andrés Manuel López Obrador has largely refused to spend money to compensate fishermen for staying outside the vaquita sanctuary and to ban the use of gill nets, or to monitor their presence or departure areas.

Sea Shepherd has been working in the Gulf alongside the Mexican Navy to discourage illegal fishing in the protected area. Government protection efforts have been patchy at best, and are also often met with violent opposition from local fishermen.